Rule Organization For Efficient Transaction Pattern Matching

ABSTRACT

Efficiently identifying transactions processed by a software application, such as a server application is disclosed. In one embodiment, transactions are identified by applying a set of rules to communications between a client and server to determine whether certain patterns are in the communications. For example, the rules may look for some combination of parameters in the transactions. As a particular example, the rules may be used to look for parameters in HTTP requests. The rules are organized in a way that allows efficient processing. For example, the rules may be organized based on the frequency with which the parameters are expected to occur in the transactions and the frequency with which each transaction is expected to occur. The rules may be updated if the expected frequencies deviate from actual frequencies, such that the rules can be organized for more efficient processing.

CLAIM OF PRIORITY

This application is a divisional application of U.S. patent applicationSer. No. 12/761,148, entitled “RULE ORGANIZATION FOR EFFICIENTTRANSACTION PATTERN MATCHING,” filed Apr. 14, 2010 and published as US2011/0258209 on Oct. 20, 2011, and incorporated herein by reference inits entirety.

BACKGROUND OF THE INVENTION

Description of the Related Art

The growing presence of the Internet as well as other computer networkssuch as intranets and extranets has brought many new applications ine-commerce, education and other areas. Organizations increasingly relyon such applications to carry out their business or other objectives anddevote considerable resources to ensuring that the applications performas expected. To this end, various application management techniques havebeen developed.

One approach involves monitoring transactions that are performed by anapplication running on, for example, a server. Those transactions may beperformed in response to a request from a client device. For example, atransaction could be a user login to a web site, a user request topurchase a product sold by the web site, a user request to use the website to sell an item, etc. A web site administrator may want to learnhow well these transactions are being performed by the software on theweb site (and/or associated web sites). Therefore, the transactionscould be monitored for performance metrics such as time to execute eachtype of transaction.

Since the software may perform many different types of transactions, thetype of transaction that is being performed needs to be properlyidentified. There are techniques for determining the type of transactionperformed for the client request. However, determining the type oftransaction being executed is not necessarily a straight forwardexercise. Some techniques for determining transaction type takeconsiderable time and/or computing power.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of an embodiment of a network monitoringsystem which monitors a network service.

FIG. 1B illustrates a flowchart of an embodiment of a process ofidentifying transactions.

FIG. 2A depicts an example data structure that has rules that may beused to identify transactions.

FIG. 2B is a flowchart of one embodiment of applying the data structureof FIG. 2A to identify transactions.

FIG. 3A is a block diagram of an embodiment of a system for monitoring anetwork service.

FIG. 3B illustrates a flowchart of an embodiment of monitoring a networkservice.

FIG. 4 is a flowchart of one embodiment of a process of initiallydeploying rules for identifying transactions to monitoring nodes.

FIG. 5 is a flowchart of one embodiment of a process of updating a datastructure that includes rules for matching transactions based on changesto frequency data.

FIG. 6 depicts a flowchart of one embodiment of a process of generatingor updating a data structure that includes rules for matchingtransactions.

FIG. 7 is a flowchart of one embodiment of a process of a updating adata structure that includes rules for matching transactions based oninput from the user.

FIG. 8A depicts an example data structure that has rules based onstrings that may be used to identify transactions.

FIG. 8B is a flowchart of one embodiment of applying a data structure ofFIG. 8A to identify transactions.

FIG. 9 is an example platform for a computer system upon whichembodiments may be practiced.

DETAILED DESCRIPTION

A method, apparatus, and system are provided for efficiently identifyingtransactions processed by a software application, such as a serverapplication. Some of the identifying of the transactions may beperformed on the server that is performing the transactions. However, byefficiently identifying the transactions, server performance is notnegatively impacted.

In one embodiment, transactions are identified by applying a set ofrules to communications between a client and server to determine whethercertain patterns are in the communications. For example, the rules maylook for some combination of parameters in the transactions. As aparticular example, the rules may be used to look for parameters in HTTPrequests. The rules are organized in a way that allows efficientprocessing. For example, the rules may be organized based on thefrequency with which the parameters are expected to occur in thetransactions and the frequency with which each transaction is expectedto occur. The rules may be updated if the expected frequencies deviatefrom actual frequencies, such that the rules can be organized for moreefficient processing.

Network Service Monitoring

Technology disclosed herein may be implemented at least in part by anetwork service monitoring system that monitors a network service suchas a web service, though other network services may be monitored aswell. Generally, a network service can be provided over the Internet, anintranet, an extranet, a private network or other network or networksand is not limited to network services which are provided via the WorldWide Web. Although some examples discussed below reference a webservice, the technology discussed herein applies generally to otherservices that are connected to or in communication with a network orother means of communication.

FIG. 1A depicts one example network service monitoring system. Thesystem includes one or more network servers 140, one or more applicationservers 150, a traffic monitoring system 180, and an applicationmonitoring system 190. Client devices 110 access the network servers 140over network 120.

The network service may be provided by a network server 140 and anapplication server 150. In practice, any number of servers or othercomputing devices which are connected in any configuration can be used.Network server 140 sends traffic to and receives traffic from clientdevice 110 over network 120, such as the Internet or other WAN, a LAN,intranet, extranet, private network or other network or networks. Inpractice, a number of client devices can communicate with the networkserver 140.

Application server 150 may be in communication with network server 140.In particular, when network server 140 receives a request from clientdevice 110, network server 140 may relay the request to applicationserver 150 for processing. The client device 110 can be a laptop, PC,workstation, cell phone, PDA, or other computing device which isoperated by an end user. Or, the client device can be an automatedcomputing device such a server. Application server 150 processes therequest received from the network server 140 and sends a correspondingresponse to the client device 110 via the network server 140.

The application monitoring system 190 may monitor the execution of oneor more applications 151 of the network service. In one possibleapproach, the application monitoring system 190 uses one or more agents,such as agents 152, which may be considered part of the applicationmonitoring system 190, though agents 152 are illustrated as separateblocks in FIG. 1A. Agent 152 and application monitoring system 190 maymonitor the execution of one or more applications 151 at the applicationserver 150, generate application runtime data, which represents theexecution of components of the application responsive to the requests,and process the generated application runtime data 143. In someembodiments, application monitoring system 190 may be used to monitorthe execution of an application or other code at some other server, suchas network server 140.

For example, the application monitoring system 190 may monitor theperformance of one or more applications 151 and generate correspondingapplication runtime data 143 which identifies, e.g., components whichare invoked in one or more execution paths such as threads and/orprocesses of the application. Example components can include servlets,Java Server Pages, Enterprise Java Beans Java Database Connectivitycomponents and/or Microsoft NET components. The application runtime data143 can provide a transaction trace, for example, which indicates thetime intervals in which the components were invoked.

The traffic monitoring system 180 may observe network traffic sent andreceived by a network service, and may monitor traffic providedaccording to any type of network protocol. Although the trafficmonitoring system 180 is depicted a monitoring traffic between client110 and network server 140, the traffic monitoring system 180 may belocated elsewhere. For example, traffic monitoring system 180 mayobserve traffic between network server 140 and application server 150.

As discussed herein, transactions that are processed by the networkservice may be efficiently identified. A transaction can refer to aseries of related network communications that perform a function. Forexample, when a user logs in to a web site, the series of relatednetwork communications could be a “login transaction.” If is userpurchases a book on an e-commerce web site, this could be a “buytransaction.” Either traffic monitoring system 180, or the agents 152,or both may identify transactions that are processed by the networkservice. The application monitoring system 190 may send rules 141 to thetraffic monitoring system 180 and/or the agents 152. The rules 141 maybe used to efficiently identify transactions. The traffic monitoringsystem 180 and/or the agents 152 may send frequency data 142 to theapplication monitoring system 190. The frequency data 142 will bediscussed in greater detail below. Briefly, the frequency data may bedetermined based on how frequently different transactions are processedand how frequently different parameters associated with the transactionsappear in the network traffic. The application monitoring system 190 mayuse the frequency data 142 to modify the rules 141 such that they may beexecuted more efficiently by the agents 152 and/or traffic monitoringsystem 180.

FIG. 1B illustrates a flowchart of an embodiment of a process ofidentifying transactions that are processed by applications 151. Asmentioned, transactions may be identified by the traffic monitoringsystem 180 and/or agents 152. Note that in this and the other flowchartsprovided, the steps indicated are not necessarily performed one at atime in the order indicated, but may occur simultaneously, at least inpart, and/or in another order.

In step 101, rules 141 for identifying the transactions are initiallydeployed on monitoring nodes. The monitoring nodes could be the agents152 and/or the traffic monitoring system 180. The rules 141 may beorganized in a way that helps them to be efficiently applied. In oneembodiment, the rules 141 are included in a data structure that includesparameters associated with the transactions and rules for identifyingthe transactions. FIG. 2A depicts an example data structure thatincludes rules used to identify transactions. The data structure isorganized in a way that allows the rules to be efficiently applied. FIG.2A will be discussed in more detail below. Further details of thedeployment of the initial rules are also discussed below.

In step 102, communications between the clients 102 and applications 151are monitored. In one embodiment, agents 152 monitor the communications.In some embodiments, the agents 152 monitor the communications bymonitoring the application 151. Further details of agent monitoring arediscussed below. In one embodiment, communications in traffic sent toapplication 151, such as traffic sent between client device 110 and webserver 140 over network 120, is observed by traffic monitoring system180. The observation can involve passively copying the traffic at someintermediate point between the client 110 and the application 151 via atap or mirror port, for instance, or intercepting the traffic, copyingthe intercepted traffic and relaying the intercepted traffic it to itsintended destination. Note that monitoring communications may includemonitoring requests sent from client 110 to network server 140 and/orresponses sent from network server 140 back to client 110.

At step 104, the rules 141 are applied to identify which transactionsare processed by the network service. For example, rules 141 are appliedto identify which transactions are processed by the applications 151. Asmentioned, the rules 141 may have a certain organization. For example,the rules 141 may be organized based on expected patterns in thetransactions. Therefore, the rules 141 may be applied based on theorganization. In one embodiment, applying the rules 141 is achieved byusing a data structure such as the one in FIG. 2A. In this case, theorganization is based on the data structure. In one embodiment, patternsin the communications are detected in order to match patterns withtransactions. Transactions can be detected based on transactiondefinitions which specify the existence or non-existence or combinationthereof of a set of name/value pairs, e.g., parameters, which are foundin the communications.

At step 106, the communications are analyzed. In one embodiment, thestep 106 includes determining the frequency with which each of thetransactions is identified and the frequency with which each of thepatterns appear in the transactions. In some embodiments, the patternsare based on parameters (e.g., HTTP parameters). In some embodiments,the patterns are based on strings (e.g., arbitrary strings of data)These determined frequencies may be termed “frequency data.” In someembodiments, the frequency data 142 is transmitted from either theagents 152 or traffic monitoring system 180 to the applicationmonitoring system 190. In one embodiment, the agents 152 analyze thecommunications. In one embodiment, the traffic monitoring system 180analyzes the communications.

In step 108, the rules 141 are updated based on the analysis of thecommunications. Updating the rules 141 may include modifying theorganization of the rules. For example, the organization of the datastructure of FIG. 2A may be changed. In some embodiments, the rules 141are updated based on the frequency with which each of the transactionswas identified and/or the frequency with which each of the patternsappeared in the transactions. Updating the rules 141 may organize therules in a way that they can be more efficiently processed at themonitoring nodes.

In step 111, the updated rules are provided to the monitoring nodes. Forexample, the application monitoring system 190 provides the updatedrules to the agents 152 and/or the traffic monitoring system 180. Theprocess may then return to step 102, wherein the updated rules are usedto identify transactions.

FIG. 2A depicts an example of rules 141 that may be used to identifytransactions. In this example the rules 141 include a data structurethat is organized in a way that allows the rules to be efficientlyapplied. The data structure includes parameter nodes 130 a-130 e andrule nodes 132 a-132 c. In this embodiment, the data structure includesa tree. For purposes of discussion, the tree will be considered to bethe portion that includes the parameter nodes 130 a-130 e. In general,the tree may be traversed from the root node 130 a downward to arrive atone of the leaf parameter nodes 130 c, 130 d, 130 e. Each of the leafparameter nodes 130 c, 130 d, 130 e points to (or includes) a rule node132 a-132 c. Note that the example data structure is simplified and thata typical implementation would have many more nodes. For example, therecould be many more parameter nodes 130 and the tree could have morelevels. The tree may be structured such that parameters that areexpected to occur with a greater frequency in the transactions areplaced closer to the root. If the frequency with which the parametersoccur in the transactions changes (or deviates from expected values),the tree may be re-organized. For example, parameter nodes 130 may bemoved to different locations and/or the content of parameter nodes 130may change. In some embodiments, parameters that are expected to appearmore frequently are moved closer to the root. The re-organization of thetree is one way of re-organizing the rules 141 and may help to create amore efficient data structure that can be parsed more quickly.

Each rule may be associated with a certain transaction. For example, ifRule A is true, then transaction A is identified. In some embodiments,the rules in each rule node are ordered based on the frequency withwhich the transaction associated with rule either is expected to occuror has been identified as actually occurring. For example, in rule node132 b, Rule A has a frequency of 50 percent, Rule B has a frequency of30 percent, and Rule C has a frequency of 20 percent. Over time if thefrequency changes, the rules may be re-ordered. Re-ordering the rules ina rule node is one way to re-organize the rules and may lead to a moreefficient data structure. In some embodiments, the rules that appear ina given rule node may be changed to re-organize the rules. Furtherdetails of how the tree is generated are discussed below.

FIG. 2B is a flowchart of one embodiment of applying a data structure toidentify transactions. The process may be performed by agents 152 and/ortraffic monitoring system 160, for example. The process is oneembodiment of step 104 of FIG. 1B. Reference will be made to the exampledata structure of FIG. 2A when discussing the process flow.

In step 202, parameters in the communications are identified. In someembodiments, this may include analyzing HTTP requests to generate anHTTP parameter name/value pair. Table 1 and Table 2 below provide oneexample of an HTTP request that can be parsed to determine name/valuepairs. Note that the parameters could be from a protocol other thanHTTP.

In step 204, the data structure is traversed from root parameter node130 a to one of the leaf parameter nodes 130 c, 130 d, 130 e based inthe identified parameters. In one embodiment, the tree is traversed bycomparing the identified parameters with the parameters that areincluded in a parameter node 130. For example, the root parameter node130 a includes “Param1.” If Param1 exists in the communications, thenthe “yes” branch is taken to parameter node 130 b. However, if Param1does not exist in the communications, then the “no” branch is taken toparameter node 130 e. Note that parameter node 130 e is a leaf parameternode; therefore, traversing the tree is complete for that path.

In the case in which the “yes” branch was taken to node 130 b, then adetermination is made whether both Param1 and Param2 exist in thecommunications. If they both exist, then the “yes” branch is taken toparameter node 130 c. If one does not exist, then the “no” branch istaken to parameter node 130 d. At this point, one of the leaf parameternodes has been reached.

In step 206, the rules that are linked to the leaf parameter node areapplied in order. Applying the rules may stop when a rule evaluates totrue. However, it is not required that evaluation stop when one ruleevaluates to true. For example, if traversing the tree arrived at theroot parameter node 130 d, then the rules in rule set 132 b may beapplied in order. Note that the rules are ordered based on the frequencywith which their associated transactions are expected to occur. Thus,first Rule A is evaluated. If Rule A evaluates to true, processing maystop with the determination that Transaction A has been identified. IfRule A does not evaluate to true, then Rule B may be evaluated. Then,Rule C may be evaluated. Note that the data structure is organized suchthat at least one of the rules in the rule set 132 b should evaluate totrue. If more than one rule evaluates to true, then a tie-breakingprocedure may be used. An example tie-breaking procedure is to selectthe most complex rule.

Prior to discussing further details of identifying transactions, anexample system and method of an embodiment for monitoring an applicationwill be discussed. As mentioned, in some embodiments, the transactionsare identified by agents 152 in the system for monitoring anapplication. FIG. 3A is a block diagram of an embodiment of a system formonitoring an application. As discussed above with respect to FIG. 1A,the application monitoring system 190 may be used to monitor anapplication 151 and generate application runtime data. In oneembodiment, FIG. 3A provides more detail for application server 150 andapplication monitoring system 190 of FIG. 1A. The system includesapplication server 150 which is in communication with Enterprise Manager155 which, in turn, is in communication with example workstations 195and database 430. Application server 150 includes managed application151, which includes agent 152 and example probes 153 and 154.Application 151 can be a Java application or a different type ofapplication.

Behavior of the application 151 can be monitored by instrumentingbytecode or intermediate language (IL) code of the application, byplugging into an exit built into the application or network server, orby any other monitoring technique. For example, information from theapplication 151 can also be obtained using probes 153 and 154. Inpractice, many such probes can be used to obtain information regardingdifferent components of the application.

In one embodiment, a probe builder (not pictured) instruments (e.g.,modifies) bytecode for application 151 to add the probes 153 and 154 andadditional code. In another approach, developers add probes to theapplication source code. The probes may measure specific pieces ofinformation regarding the application without changing the application'sbusiness logic. The probe builder may also add agent 152 which may beinstalled on the same machine as application 151 or a separate machine.Once the probes have been installed in the application, or a monitoringcapability has otherwise been provided, the application is referred toas a managed application. More information about instrumenting bytecodecan be found in U.S. Pat. No. 6,260,187, “System For Modifying ObjectOriented Code” by Lewis K. Cirne, and U.S. patent application Ser. No.09/795,901, “Adding Functionality To Existing Code At Exits,” filed onFeb. 28, 2001, each of which is incorporated herein by reference in itsentirety.

As managed application 151 runs, probes 153 and 154 send data to agent152. In one embodiment, probes 153 and 154 may be implemented in objectsand other code that write data, change data or otherwise cause the stateof an application server to change. Agent 152 then collects, summarizesand sends the data, referred to as application runtime data, toEnterprise Manager 155. In response, Enterprise Manager 155 runsrequested calculations, makes application runtime data available toworkstations 195 and, optionally, sends the application runtime data todatabase 430 for later analysis. More information regarding monitoringan application using probes can be found in U.S. Patent App. Pub. No.2004/0075690, published Apr. 22, 2004, titled, “User Interface ForViewing Performance Information About Transactions”, by Lewis K. Cirne,incorporated herein by reference.

Workstations 195 provide a graphical interface for viewing applicationruntime data such as by creating custom views which can be monitored bya human operator. The workstations can include windows which provide aset of customizable views and depict alerts and calculators that filterapplication runtime data so that the data can be viewed in a meaningfulway. The elements of the workstation that organize, manipulate, filterand display application runtime data can include actions, alerts,calculators, dashboards, persistent collections, metric groupings,comparisons, smart triggers and SNMP collections. In some embodiments,the workstations 195 are used to allow a user to define rules formatching transactions.

In one embodiment of the system of FIG. 3A, one or more components arerunning on different computing devices. Alternatively, the componentscan run on the same computing device. A computing device on which eachcomponent may run is discussed in more detail below with respect to FIG.9.

In some embodiments, the agents 152 monitor the applications 151 andtransfer application runtime data to the application monitoring system190, where the data is analyzed and reported to user. FIG. 3Billustrates a flowchart of an embodiment of a process of monitoringapplications 151. The process may be performed in the example system ofFIG. 3A. An application 151 is monitored by agents 152 at step 112.Monitoring may involve agents 152 determining which transactions ofapplication server 150 are processed and the duration in which they areinvoked when the application processes a client request.

Application runtime data 143 based on the monitoring of the applicationis generated at step 114. The generated application runtime data 143 canindicate the application components involved in processing a request,the duration that each component consumed in processing a request, andother information. The application runtime data 143 can be generated byagent 152, in one possible approach, after which the agent 152 mayforward the generated application runtime data 143 to applicationmonitoring system 190, which can exist outside of application server150, in one embodiment. Generally, application runtime data 143 caninclude information such as average method execution time, a methodinvocation rate per second or per interval, a count of methodinvocations, a concurrency metric indicating number of methodinvocations that have started but not finished per interval, and astalled metric indicating a number of method invocations that havestarted whose method invocation times have exceeded a specific thresholdper interval. Further, application runtime data can identify a garbagecollection heap size, a bandwidth metric indicating file and socketactivity, a number of threads, system logs, exceptions, memory leaks andcomponent interactions. Note that the application runtime data may belinked to particular transactions.

The application runtime data 143 may be processed and reported byapplication monitoring system 190 at step 116 such as by aggregating thedata, storing the data, and providing the data to an operator through aninterface or other output 195.

In some embodiments, traffic monitoring system 180 and applicationmonitoring system 190 communicate with each other to enable associationof the transactions and application runtime data. In some embodiments,the traffic 180 and application monitoring systems 190 may be usedtogether, e.g., integrated, to provide diagnostics, statistics and otherdata regarding the operation of a web service, network system or othersystem. The integrated data may be analyzed by an operator oradministrator, viewed in reports, and processed to identify systemhealth, performance or other issues of concern, for instance. Furtherdetails of a traffic monitoring system 180 and an application monitoringsystem 190 communicating with each other to enable association oftransactions and application runtime data are discussed in PublishedU.S. Patent Application 2007/0266149, entitled “Integrating TrafficMonitoring and Application Runtime Data,” filed on Dec. 4, 2006, whichis hereby incorporated by reference in its entirety for all purposes.

Now that example systems have been discussed, further details ofidentifying transactions will be discussed. Reference will be made tothe system of FIG. 1A and the more detailed system of FIG. 3A. However,it will be appreciated that identifying transactions is not limited tothose example systems. FIG. 4 is a flowchart of one embodiment of aprocess 400 of initially deploying rules for identifying transactions tothe monitoring nodes. Process 400 is one embodiment of step 101 of FIG.1B. In step 402, a user defines an initial set of rules for identifyingtransactions. The user may input the rules through workstation 195. Insome embodiments, the rules are used to match patterns in thecommunications between the client 110 and application server 150.

In one embodiment, each rule contains a set of parameters identified bya name. Each parameter name may have a match value, which may becompared to a parameter value in the communications (e.g., in anincoming request from the client). As examples, the match value could bea literal value or a regular expression pattern. In one embodiment, fora transaction to be matched by a rule, all the elements in thetransaction request should match all the parameters in the rule, or beabsent in the rule. If more than one rule matches the transaction, atie-break strategy may be used. One example tie-breaker is to considerthe most complicated rule to be the one that matches the transaction.Any form of pattern matching may be used, from simple wild-card patternmatching to more complex regular expression pattern matching.

For example, URL parameters include name/value pairs that appear in theHTTP request line before the first “?” character or in special requestheaders such as the Host: request header. For example, assume the useris interested in monitoring a login process which involves one or moreweb pages which allow a user to login to a web site. The trainedoperator can recognize such web pages by their URLs. Therefore, the usercan assign a rule based on the URL. Cookie parameters may includename/value pairs that appear in the Cookie: request header. Postparameters may include name/value pairs that appear in the HTTP POSTrequest-body. Query parameters may include name/value pairs that appearin the HTTP request line after the first “?” character. Sessionparameters may include name/value pairs that appear in such an encodedor encrypted value. Name and value specifications may specify an exactvalue for exact matching or a pattern for pattern matching.

In step 404, the EM 155 generates an initial data structure for the ruleset. The data structure in FIG. 2A has been provided as one simpleexample of a data structure. Further details of generating a datastructure are described below with reference to FIG. 6.

In step 406, the data structure is provided to the monitoring nodes. Insome embodiments, agents 152 are provided with the initial datastructure. In some embodiments, a traffic monitoring system 180 isprovided with the initial data structure.

FIG. 5 is a flowchart of one embodiment of a process 500 of updating adata structure that includes rules for matching transactions based onchanges to the frequency data. Process 500 is one embodiment of step 108of FIG. 1B in which rules are updated based on analysis of thecommunications between the client and application. Process 500 may beginafter the communications are analyzed in step 106 of FIG. 1B. Recallthat the analysis of the communications may include determining whetheractual occurrence of parameters deviates from expected occurrence of theparameters. Also recall that the analysis of the communications mayinclude determining whether actual occurrence of transactions deviatesfrom expected occurrence of the transactions.

In step 502, a monitoring node detects that the actual frequency ofeither patterns or transactions deviates from expected frequency by morethan a pre-determined amount. For example, with respect to a pattern,the monitoring node may determine that frequency of an HTTP parameterdeviates from expected occurrence. The pre-determined amount may be anyvalue and could be upward or downward. For example, a Buy Transactionmight be expected to occur 50 percent of the time; however, a certainmonitoring node might determine that the Buy Transaction has actuallyoccurred 40 percent of the time. If this deviation is consideredsignificant (e.g., is more than a pre-determined amount), then themonitoring node determines that this deviation should be reported. Asanother example, a certain parameter might be expected to occur 12percent of the time; however, is found to actually occur 15 percent ofthe time. If this deviation is considered significant (e.g., is morethan a pre-determined amount), then the monitoring node determines thatthis deviation should be reported. Note that the monitoring node maydetermine whether deviations occur at any time. For example, themonitoring node could periodically compare the expected frequencies withactual frequencies. Also note that each monitoring node may perform step502 on its own.

In step 504, the monitoring node sends frequency data 142 to the EM 155.When reporting a deviation of one transaction, the monitoring node mayreport current data for all other transactions or any set oftransactions. When reporting a deviation of one pattern (e.g.,parameter), the monitoring node may report current data for all otherparameters or any set of parameters. Also note that when reporting adeviation of a given parameter, the monitoring node might report currentdata for all transactions for which the rule contains the parameter,some set of those transactions for which the rule contains theparameter, all transactions, no transactions unless a deviation isfound, etc. Likewise, when determining that a transaction has adeviation from expected occurrence, the monitoring node might reportcurrent data for all parameters in the rule associated with thetransaction, some set of those parameters, all parameters, no parametersunless a deviation is found, etc.

In step 506, the EM 155 determines whether the rules 141 (e.g., datastructure) should be updated based on the changes in the frequency data.Since there may be more than one monitoring node, the EM 155 mayaggregate the frequency data from the monitoring nodes and make adetermination of whether the aggregated data suggests the data structureshould be updated. As mentioned, updating the data structure can lead tomore efficient processing at the monitoring nodes. However, there may bea slight cost in making the updates; therefore, updates may be held offuntil changes are significant enough to offset the costs. Note thatsince the EM 155 performs the actual update to the data structure, theapplication servers 150 are not impacted by the update. However, therewill be a certain amount of network traffic to send the updates to themonitoring nodes. It may be desirable to avoid adding substantialnetwork traffic when making updates.

If the EM 155 determines that that data structure should be updated,then it is updated in step 508. Note that the organization of the datastructure may be modified in step 508. For example, if the rules are ina data structure that includes a tree having a root, updating the rulesmay include placing parameters that occur in the communications with agreater frequency closer to the root of the tree. In some embodiments,there is a set of one or more rules at each lowest node in the tree. Inthis case, updating the rules may include ordering the rules at each ofthe lowest nodes of the tree based on the frequency with which thetransactions are received. Further details of how the data structure isgenerated and updated are discussed below with respect to FIG. 7. If theEM 155 determines that updating the data structure is not yet warranted,then no changes are made. However, in either case the frequency data maybe maintained such that when additional frequency data is received,updates can be made.

In step 510, updates to the rules 141 are sent from the EM 155 to themonitoring nodes. In some embodiments, only incremental updates are sentso as to avoid adding substantial network traffic. As an example, byonly sending incremental updates, only changes to the data structure aresent.

FIG. 6 depicts a flowchart of one embodiment of a process 600 ofgenerating or updating a data structure that includes rules for matchingtransactions. Process 600 may be used to create or update a datastructure such as the example depicted in FIG. 2A. Process 600 is oneembodiment of step 108 of FIG. 1B of updating the rules. Process 600 isone embodiment of step 404 of FIG. 4 of defining the initial datastructure having the rules. Process 600 is one embodiment of step 508 ofFIG. 5 of updating the rules a data structure having the rules. Process600 may be performed by the EM 155. In step 602, a rule set is accessed.In one embodiment, the rule set is provided by the user as described instep 402 of FIG. 4, for example. If process 600 is being used to updatethe data structure, then the rule set may be accessed from storage. Forexample, the database 430 may be used to store the rule set that waspreviously provided by the user.

In step 604, parameters that are used in the rule set are identified. Asmentioned, each rule may be associated with one or more parameters. Forexample, the rules may refer to various HTTP parameters.

In step 606, a frequency is assigned to each parameter. If noinformation has yet been provided regarding the actual frequency of theparameters, the initial frequency may be an estimate. The estimate maybe made in many ways such as assigning an arbitrary value to parameter,assigning a value based on user input, etc. If frequency data 142 hasbeen provided regarding the actual frequency of the parameters, theparameter frequency may be based on the frequency data 142. Note that inthis latter case, the frequency data 142 may be used to alter theprevious frequency values for the parameters.

In step 608, a tree is generated based on the parameters, parameterfrequencies, and rules. An example, tree is depicted in FIG. 2A.Specifically, the parameter nodes 130 form the tree. In someembodiments, the tree is a binary tree. For example each parameter node130 that is not a leaf node may have two children. In one embodiment, aparameter node 130 includes one or more parameters. In one embodiment,each parameter node 130 corresponds to an algorithm decision on whatsubset of rules are still possible candidates for matching. For example,the tree in FIG. 2A is for a case with Rules A-F. If the algorithmdecision at parameter node 130 a is “no” then Rules E and F remain aspossible matches. If the algorithm decision at parameter node 130 a is“yes” then Rules A, B, C and D remain as possible matches.

In one embodiment, the two child nodes for a given parameter node 130are arrived at based on whether the parameters in the given parameternode 130 exist. For example, “yes” and “no” branches appear in the treeof FIG. 2A. In one embodiment, each parameter node 130 has decedent(e.g., children, grandchildren, etc.) nodes with other possibleparameters. For example, parameter node 130 a has decedent nodes withparameters Param5 (at node 103 e) and Param2, Param3, and Param4 on theother path.

In general, parameters that are expected to occur more frequently mayappear closer to the root of the tree. For example, Param1 appears atthe root of the tree in FIG. 2A. This may be because Param1 is expectedto occur more frequently than other parameters. Likewise, Param2 may beexpected to occur more frequently than Param3 or Param4.

In some embodiments, the tree is balanced, to at least some extent, inorder to create a more efficient structure. Note that the tree is notrequired to be completely balanced. For example, the tree in FIG. 2A isnot completely balanced because leaf parameter node 130 e is closer tothe root parameter node 130 a than the other leaf parameter nodes 130 c,130 d.

In step 610, rules for each leaf parameter node 130 are identified. Thismay include identifying rules that contain one or more of the parametersin the path from leaf parameter node to root parameter node. Forexample, for leaf parameter node 130 d, the parameters on the pathinclude Param1, Param2, and Param4. A rule may contain one or more ofthe parameters. Thus, a rule is not required to contain all of theseparameters. Thus, a set of rules for each leaf parameter node 130 isidentified. Note this is not necessarily the final sets depicted in FIG.2A.

In step 612, rules that share common parameters are identified in orderto shorten the tree. However, note that the rules do not need to havethe identical parameters. For example, referring to the tree in FIG. 2A,Rules C and D may share common parameters Param1, Param2 and Param3.However, Rule C may have additional parameters such as Param6, Param7,and Param8 (not depicted in the tree of FIG. 2A). In this case, the treeis not required to have additional parameter nodes for Param6, Param7,and Param8. Rather, the tree can stop at leaf parameter node 130 c. Thisshortens the tree and, therefore, may lead to more efficient processingwhen using the tree to identify transactions.

In step 614, rules that share a common subset of regular expressions areassociated with each other. For example, consider rules that have thefollowing regular expressions:

www.google.com

www.google. 1.com

maps.google.com

The rules share the regular expression *.google.* If that regularexpression is not found in the data traffic, the none of the rules willmatch. Therefore, the rules may be associated with one another tominimize the number of comparisons. For example, a notation may be addedto the tree that Rules B and C are associated in this manner. Therefore,when the monitoring node looks for the common subset of regularexpression in the data traffic, the monitoring node may stop processingfor Rules B and C if the common subset of regular expression is notfound.

In step 616, a frequency is assigned to each rule. This frequency may bean expected or actual frequency with which a rule is expected to oractually matches. Since rules may correspond to transactions, thefrequency may be an expected or actual frequency with which atransactions is expected to or actually matches. The data structure ofFIG. 2A depicts example frequencies assigned to rules. The values forthe frequencies may be determined in a number of ways. For example, ifno frequency data 142 exists, the frequency values could be assignedarbitrarily. The actual frequency data 142 from the monitoring nodes maybe used to refine those values. Thus, when the monitoring nodes sendactual frequency data 142, that data may be used to update the frequencyvalues. In some case, the frequency values may be based on user input.For example, a user could input an expected frequency for a BuyTransaction.

In step 618, the rules are ordered based on the rule frequencies. Forexample, referring to FIG. 2A, the rules in each subset associated witha leaf parameter node are ordered form high to low. Therefore, ruleprocessing may be efficiently performed at the monitoring nodes. Afterthe data structure has been generated or updated, it may then beprovided to the monitoring nodes. Note that it is not required that theentire data structure be provided. For example, if performing step 111of FIG. 1B, only those portions that are necessary to provide theupdates need to be provided.

From time to time, the user may decide that the rules for identifyingtransactions should be changed. FIG. 7 is a flowchart of one embodimentof a process 700 of updating the data structure based on input from theuser. In step 702, the user modifies the rule set. For example, the useraccesses a work station 195 and accesses a previous version of the ruleset that is stored in database 430 and modifies it. The user might addnew rules or delete former rules. For existing rules, the user might addor delete parameters. The user might also change the conditions uponwhich the rule evaluates to true.

In step 704, the EM 155 updates the organization of the rules. Theprocess of FIG. 6 may be applied to update the rules based on a new ruleset. In step 706, the updated rules are provided to the monitoringnodes. For example, agents 152 and/or traffic monitoring system 180 isprovided with a new rules or at least updated portions of the rules, aswell as the organization of the rules.

As discussed in step 102 of FIG. 1B, monitoring nodes may monitorcommunications between client 110 and application 151. In someembodiments, this may include analyzing HTTP requests to generate anHTTP parameter name/value pair. For example, a typical HTTP post requestthat can be parsed is shown in Table 1.

TABLE 1 Request-line: POST /dir/file.html?query1=q1&query2=q2HTTP/1.1\r\n request-headers: Content-type:application/x-www-form-urlencoded\r\n  Host: www.company.com\r\n Cookie: cookie1=c1; cookie2=c2\r\n  Referer:https://www.company.com/dir/home.html?action=login\r\n  \r\nrequest-body: post1=p1&post2=p2

An example of an HTTP parameter list that derived from parsing the aboverequest is shown in Table 2. Each parameter includes a type andname/value pair.

TABLE 2 type=″Query,″ name=″query1″, value=″q1″ type=″Query,″name=″query2″, value=″q2″ type=″Cookie,″ name=″cookie1″, value=″c1″type=″Cookie,″ name=″cookie2″, value=″c2″ type=″Post,″ name=″post1″,value=″p1″ type=″Post,″ name=″post2″, value=″p2″ type=″Url,″name=″Host″, value=″www.company.com″ type=″Url,″ name=″Path″,value=″/dir/file.html″ type=″Url,″name=″Url″,value=″www.company.com/dir/file.html?query1=q1&query2=q2″type=″Url,″name=″Referer″,value=″www.company.com/dir/home.html?action=login″

The parameter list data may be retrieved from the HTTP request inTable 1. In particular, the parameter list query data can be retrievedfrom the request-line of the request, the cookie data can be retrievedfrom the request headers, the post data can be retrieved from therequest body, and the URL data can be retrieved from the request headerand request line. After determining the name/value pairs for the HTTPparameters, the monitoring node may apply the rules thereto to identifythe transaction.

Note that it is not required that the parameters be HTTP parameters.Moreover, note that it is not an absolute requirement that the rules bebased on parameters in the data traffic. In one embodiment, the datatraffic (e.g., communications) is divided into “chunks” of data. Forexample, instead of looking for specific parameters that are in acertain position in the data traffic in accordance with some standard,such as an HTTP standard, the data traffic could be cut into chunks thatdo not necessarily correspond to certain parameters in the standard.Rules can still be assigned to match patterns in the chunks. Forexample, a rule could be to look for a certain string in chunk 1,another string in chuck 2, etc. In this case, instead of supplyingparameters and parameter frequency to the monitoring nodes, strings andstring frequencies could be provided. Because the strings do notnecessarily correspond to any specific parameter, the strings may bereferred to as “arbitrary strings.”

As one example, the tree structure of FIG. 2A could be modified byreplacing parameters with strings. FIG. 8A depicts one embodiment of atree having string nodes 830, instead of parameter nodes 130. In thisexample, strings that are expected to occur with a higher frequencycould appear higher in the tree. Therefore, the rules may be organizedbased on the strings. The organization of the tree could be modifiedbased on actual frequencies with which strings appear in the datatraffic and/or actual frequencies with which transactions areidentified.

FIG. 8B is a flowchart of one embodiment of applying a data structure toidentify transactions. The process may be performed by agents 152 and/ortraffic monitoring system 160, for example. The process is oneembodiment of step 104 of FIG. 1B. Reference will be made to the exampledata structure of FIG. 8A when discussing the process flow.

In step 802, the communications are divided into chunks. For example,starting with some reference point in the traffic (e.g., the header of apacket), the data traffic is divided into chucks of some pre-determinedsize. Chunks may be of different size from each other.

In step 804, the data structure of FIG. 8A is traversed from root stringnode 830 a to one of the leaf string nodes 830 c, 830 d, 830 e basedwhether strings are present in the data traffic, as it is chunked. Inone embodiment, the tree is traversed by comparing a chunk with one thestings in a given string node 830.

In step 806, the rules that are linked to the leaf string node areapplied in order. This may be similar to the case in which rules arebased on parameters.

FIG. 9 is a block diagram of an embodiment of a computing system for usewith the present technology. The computing system may be used to as aplatform for client device 110, network server 140, application server150, Enterprise Manager 155, traffic monitoring system 180, applicationmonitoring system 190, workstations 195, database 430, etc.

The computer system includes one or more processors 550 and main memory552 which stores, in part, instructions and data for execution byprocessor unit 550. If the system of the present invention is wholly orpartially implemented in software, main memory 552 can store theexecutable code when in operation. Also provided are a mass storagedevice 554, peripheral device(s) 556, user input device(s) 560, outputdevices 558, portable storage medium drive(s) 562, a graphics subsystem564 and an output display 566. For simplicity, the components aredepicted as being connected via a single bus 568. However, thecomponents may be connected through one or more data transport means.For example, processor unit 550 and main memory 552 may be connected viaa local microprocessor bus, and the mass storage device 554, peripheraldevice(s) 556, portable storage medium drive(s) 562, and graphicssubsystem 564 may be connected via one or more input/output (I/O) buses.Mass storage device 554, which may be implemented with a magnetic diskdrive or an optical disk drive, is a non-volatile storage device forstoring data and instructions for use by processor unit 550. In oneembodiment, mass storage device 554 stores the system software forimplementing the present invention for purposes of loading to mainmemory 552.

Portable storage medium drive 562 operates with a portable non-volatilestorage medium, such as a floppy disk, to input and output data and codeto and from the computer system. In one embodiment, the system softwarefor implementing the present invention is stored on such a portablemedium, and is input to the computer system via the portable storagemedium drive 562. Peripheral device(s) 556 may include any type ofcomputer support device, such as an input/output (I/O) interface, to addadditional functionality to the computer system. For example, peripheraldevice(s) 556 may include a network interface for connecting thecomputer system to a network, a modem, a router, etc.

User input device(s) 560 provides a portion of a user interface. Userinput device(s) 560 may include an alpha-numeric keypad for inputtingalpha-numeric and other information, or a pointing device, such as amouse, a trackball, stylus, or cursor direction keys. In order todisplay textual and graphical information, the computer system includesgraphics subsystem 564 and output display 566. Output display 566 mayinclude a cathode ray tube (CRT) display, liquid crystal display (LCD)or other suitable display device. Graphics subsystem 564 receivestextual and graphical information, and processes the information foroutput to output display 566. Additionally, the computer system includesoutput devices 558. Examples of suitable output devices includespeakers, printers, network interfaces, monitors, etc.

The components contained in the computer system are those typicallyfound in computer systems suitable for use with the present invention,and are intended to represent a broad category of such computercomponents that are well known in the art. Thus, the computer system canbe a personal computer, hand held computing device, telephone, mobilecomputing device, workstation, server, minicomputer, mainframe computer,or any other computing device. The computer system can also includedifferent bus configurations, networked platforms, multi-processorplatforms, etc. Various operating systems can be used including Unix,Linux, Windows, Macintosh OS, Palm OS, and other suitable operatingsystems.

One embodiment disclosed herein includes a method of a method ofupdating rules for identifying transactions. The method may include thefollowing. Communications between clients and an application thatprocesses transactions are monitored. Rules to identify whichtransactions are processed by the applications are applied. The rulesare applied to based on how the rules are organized. The communicationsare analyzed. The organization of the rules is updated based onanalyzing the communications.

One embodiment disclosed herein includes at least one processor readablestorage device having processor readable code embodied thereon forprogramming at least one processor to perform a method. The methodcomprising monitoring communications between clients and an applicationthat processes transactions having patterns; applying rules to identifywhich transactions are processed by the application, the rules areorganized based on expected patterns in the transactions; applying therules is based on the organization; analyzing the communications; andupdating the organization of the rules based on the analyzing thecommunications.

One embodiment disclosed herein includes a monitoring system comprisingone or more storage devices having processor executable code storedthereon and one or more processors in communication with the one or morestorage devices. The code, which when executed on the one or moreprocessors, causes the one or more processors to monitor transactionsprocessed by applications. The transactions include in patterns. Thecode causes the one or more processors to apply rules to identify whichtransactions are processed by the applications. The rules are organizedbased on frequencies with which the patterns are expected to appear inthe transactions and are based on frequencies with which each of thetransactions is expected to be processed by the applications. The codecauses the one or more processors apply the rules based on theorganization of the rules. The code causes the one or more processors todetermine when actual frequency of the patterns in the transactionsdeviates from the expected frequency of the parameters or when actualfrequency of ones of the transactions deviates from the expectedfrequency of ones of the transactions. The code causes the one or moreprocessors to update the organization of the rules based on the actualfrequency of the patterns or the actual frequency of the transactions.

One embodiment disclosed herein includes a method of updating a datastructure for identifying transactions, which includes the following. Afirst version of the data structure is provided to a plurality of agentsthat monitor applications that process transactions. The transactionshave one or more parameters of a plurality of parameters. The datastructure is organized based on the plurality of parameters and includesrules for identifying the transactions based on the plurality ofparameters. Transactions which are processed by the applications areidentified based on the organization of the data structure. Frequencydata is collected by the agents. The frequency data describes frequencywith which each of the transactions are identified and frequency withwhich each of the parameters appear in the transactions. The frequencydata is provided to a manager node. The organization of the datastructure is updated based on the frequency data. The updated datastructure is provided to the plurality of agents.

The foregoing detailed description of the invention has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed. Manymodifications and variations are possible in light of the aboveteaching. The described embodiments were chosen in order to best explainthe principles of the invention and its practical application, tothereby enable others skilled in the art to best utilize the inventionin various embodiments and with various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the claims appended hereto.

1. A computer-system implemented method of updating a data structure foridentifying transactions, the method comprising: providing a firstversion of the data structure to a plurality of agents that monitorapplications that process transactions, the transactions have one ormore parameters of a plurality of parameters, the data structure isorganized based on the plurality of parameters and includes rules foridentifying the transactions based on the plurality of parameters;identifying, by the agents, which transactions are processed by theapplications based on the organization of the first version of the datastructure; collecting frequency data, by the agents, that describesfrequency with which each of the transactions are identified andfrequency with which each of the parameters appear in the transactions;providing the frequency data from the agents to a manager node; updatingthe organization of the data structure based on the frequency data; andproviding the updated data structure to the plurality of agents.
 2. Thecomputer-system implemented method of claim 1, wherein the first versionof the data structure includes frequency information that includes anexpected frequency of each of the parameters and an expected frequencyof each of the transactions; wherein the agents determine whether actualfrequency of the parameters deviates from the expected frequency of eachof the parameters, the agents inform the manager node if the actualfrequency of the parameters deviates from the expected frequency; andwherein the agents determine whether actual frequency of thetransactions deviates from the expected frequency of the transactions,the agents inform the manager node if the actual frequency of thetransactions deviates from the expected frequency.
 3. Thecomputer-system implemented method of claim 1, wherein the datastructure comprises nodes including a root node and leaf nodes, whereinthe identifying which transactions are processed by the applicationsbased on the organization of the data structure includes: identifyingone or more of the parameters in a first of the transactions; traversingthe data structure from the root node to one of the leaf nodes based onthe identified one or more of the parameters.
 4. The computer-systemimplemented method of claim 1, wherein the rules each have a frequencythat is given by an expected frequency of the transaction associatedwith the rule, and identifying which transactions are processed by theapplications further includes analyzing the rules in an order that isbased on their respective frequencies.
 5. The computer-systemimplemented method of claim 3, wherein at least some of the nodes in thedata structure comprise branches to other nodes and comprise one or moreparameters, wherein the traversing the data structure from the root nodeto the leaf node based on the identified one or more of the parametersfurther comprises selecting branches based on whether the identified oneor more parameters match the parameters in the nodes.
 6. Thecomputer-system implemented method of claim 1, wherein the datastructure comprises nodes including a root node and leaf nodes, whereinat least some of the nodes have branches to other nodes and comprise oneor more parameters, wherein updating the organization of the datastructure based on the frequency data comprises placing parametershaving a greater frequency at a node closer to the root node of the datastructure than parameters having a smaller frequency.
 7. A system,comprising: a non-transitory storage device having processor executablecode stored thereon; and a processor in communication with thenon-transitory storage device, the code, which when executed on theprocessor, causes the processor to: provide a first version of a datastructure to a plurality of agents that monitor applications thatprocess transactions, the transactions have one or more patterns of aplurality of patterns, the data structure is organized based on theplurality of patterns and includes rules for identifying thetransactions based on the plurality of patterns; receive frequency data,from the agents, that describes frequency with which each of thetransactions are identified and frequency with which each of thepatterns appear in the transactions; update the organization of the datastructure based on the frequency data; and provide the updated datastructure to the plurality of agents.
 8. The system of claim 7, whereinthe data structure comprises nodes including a root node and leaf nodes,wherein at least some of the nodes have branches to other nodes andcomprise one or more patterns, wherein updating the organization of thedata structure based on the frequency data comprises placing patternshaving a greater frequency at a node closer to the root node of the datastructure than patterns having a smaller frequency.
 9. The system ofclaim 8, wherein the code causes the processor to identify rules thatcontain one or more of the patterns in a path from the root node to eachleaf node, wherein the identified rules form a set of rules associatedwith each leaf node.
 10. The system of claim 9, wherein the code causesthe processor to identify rules that share common patterns in order toshorten the data structure.
 11. The system of claim 7, wherein a managernode performs the update the organization of the data structure based onthe frequency data and provides the updated data structure to theplurality of agents, wherein the first version of the data structureincludes frequency information that includes an expected frequency ofeach of the patterns, wherein each of the agents comprises anon-transitory storage device having processor executable code storedthereon and a processor in communication with the non-transitory storagedevice, the code, which when executed on the processor, causes theprocessor on the respective agent to: determine whether actual frequencyof the patterns deviates from the expected frequency of each of thepatterns; and inform the manager node if the actual frequency of thepatterns deviates from the expected frequency.
 12. The system of claim7, wherein a manager node performs the update the organization of thedata structure based on the frequency data and provides the updated datastructure to the plurality of agents, wherein the first version of thedata structure includes frequency information that includes an expectedfrequency of each of the transactions, wherein each of the agentscomprises a non-transitory storage device having processor executablecode stored thereon and a processor in communication with thenon-transitory storage device, the code, which when executed on theprocessor, causes the processor on the respective agent to: determinewhether actual frequency of the transactions deviates from the expectedfrequency of each of the transactions; and inform the manager node ifthe actual frequency of the transactions deviates from the expectedfrequency.
 13. The system of claim 7, wherein the data structurecomprises nodes including a root node and leaf nodes, wherein at leastsome of the nodes have branches to other nodes and comprise one or morepatterns, wherein each of the agents comprises a non-transitory storagedevice having processor executable code stored thereon and a processorin communication with the non-transitory storage device, the code, whichwhen executed on the processor, causes the processor on the respectiveagent to: identify patterns in a first of the transactions; traverse thedata structure from the root node to one of the leaf nodes based on theidentified one or more of the patterns.
 14. The system of claim 13,wherein the code that causes the processor to traverse the datastructure from the root node to the leaf node based on the identifiedone or more of the patterns further causes the processor to selectbranches based on whether the identified patterns match the patterns inthe nodes.
 15. A computer system comprising: one or more non-transitorystorage devices having processor executable code stored thereon; and oneor more processors in communication with the one or more non-transitorystorage devices, the code, which when executed on the one or morenon-transitory storage devices, causes the one or more processors to:receive a first version of a data structure at a plurality of agentsthat monitor applications that process transactions, the transactionshave one or more patterns of a plurality of patterns, the data structureis organized based on the plurality of patterns and includes rules foridentifying the transactions based on the plurality of patterns;identify which transactions are processed by the applications based onthe organization of the data structure; collect frequency data, by theagents, that describes frequency with which each of the transactions areidentified and frequency with which each of the patterns appear in thetransactions; provide the frequency data to a manager node; receive anupdated data structure at the plurality of agents, the updated datastructure has an updated organization based on the frequency data. 16.The computer system of claim 15, wherein the first version of the datastructure includes frequency information that includes an expectedfrequency of each of the patterns; wherein the code causes the one ormore processors to determine whether actual frequency of the patternsdeviates from the expected frequency of each of the patterns, and informthe manager node if the actual frequency of the patterns deviates fromthe expected frequency.
 17. The computer system of claim 15, wherein thefirst version of the data structure includes frequency information thatincludes an expected frequency of each of the transactions; wherein thecode causes the one or more processors determine whether actualfrequency of the transactions deviates from the expected frequency ofeach of the transactions, and inform the manager node if the actualfrequency of the transactions deviates from the expected frequency. 18.The computer system of claim 15, wherein the data structure comprisesnodes including a root node and leaf nodes, wherein when the processoridentifies which transactions are processed by the applications based onthe organization of the data structure the code further causes the oneor more processors to: identify one or more of the patterns in a firstof the transactions; traverse the data structure from the root node toone of the leaf nodes based on the identified one or more of thepatterns.
 19. The computer system of claim 18, wherein at least some ofthe nodes in the data structure comprise branches to other nodes andcomprise one or more patterns, wherein the code that causes theprocessor to traverse the data structure from the root node to the leafnode based on the identified one or more of the patterns further causesthe processor to select branches based on whether the identified one ormore patterns match the patterns in the nodes.
 20. The computer systemof claim 19, wherein the nodes that have branches to other nodescorrespond to an algorithm decision on what subset of the transactionsare still possible candidates when traversing the data structure fromthe root node to the leaf node.